Wojciech Trocki the 2.1.0 relates to the the sdk release, not to the AeroGear Service release. It was understood that the verisons of the SDK might move on from the AeroGear Version seperately.
The reason we bumped to 2.x.x. is because we did the updates required to align the naming of the Device Checks which means there was breaking changes those methods.
We do need to revisit it as I think our approach is not clear. There was a meeting about how we wanted to approach the first one but now that we are moving on we should revist cc John Frizelle Christopher Foley